Population-based survey on cardiovascular diseases was carried out in two districts of Osaka Prefecture and in two districts of Akita Prefecture. Evaluation of blood pressure, ECG findings, ocular fundus finding and serum lipid levels was made on 4, 412 persons (ages ranging 40-69 y.o.) Following results were obtained. 1) Hypertension, hypertensive changes and cerebral apoplexy were more frequent in Akita than in two districts of Osaka. 2) Incidence of the changes due to ischemic heart diseases were relatively low in all study districts. 3) Serum lipid levels were higher in urban than in rural area.

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Myocardial protein metabolism was studied in dogs with coronary occlusion produced by ligating the anterior descending coronary artery. On the muscle homogenates obtained from the infarcted area and the uninfarcted one concentrations of nitrogenous substances and some enzymes related to protein metabolism were measured at various time intervals up to 7 days after coronary occlusion. Electrocardiographic and histological observations were also demonstrated. In the infarcted muscle, were observed considerable changes in the structural proteins which reflect the patho-anatomical changes. The infarcted tissue showed an increase in protein synthesis. This is one of the reparative mechanism after infarction. In the uninfarcted muscle, changes in the protein composition were observed, which suggest an increase in production and utilization of energy as well as the acceleration of protein synthesis.

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Three directional ballistocardiogram in 31 cases of atrial septal defect was studied. These cases were featured by a marked increase in anterior H, posterior I and posterior L (occasionally M) in posteroanterior BCG, an increase in H, I, or diastolic waves in head-foot BCG, and an increase in systolic and diastolic waves in lateral BCG. Several abnormal BCG's including both severe and mild cases were demonstrated and the importance of postero-anterior BCG in the diagnosis of atrial septal defect was discussed.

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To elucidate the effect of plasma volume on renin secretion, plasma renin activity was measured in 10 normal and hypertensive subjects during water test of VOLHARD. Water deprivation resulted in a significant increase in plasma renin activity, plasma sodium concentration and hematocrit in them except 2 patients with primary aldosteronism. Estimation of the renin activity was further carried out in S patients with diabetes insipidus. In all of them an increase in plasma renin activity as well as plasma sodium concentration was found after vasopressin injection and clinical states toward normal. These findings do not support a concept that renin secretion is dependent on a reduction in plasma sodium concentration. From the present study, it may be concluded that a dominant stimulator of renin release is a change in plasma volume rather than in plasma sodium concentration.

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A report is made of a new constructed method of the T loop which is similar to that in normal cases. The ventricle is divided into 9 segments and the direction and time history of the vector in each segment are assumed. A noteworthy point in this study is that directions are changed during the period corresponds to systole of the ventricle.

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The accumulation of carbon dioxide in the blood has often been observed in the patients with severe pulmonary disease. In these circumstances, an increased carbon dioxide might influence on the brain as well as heart and consequently cause oxygen deficiency in the brain associated with reduced cardiac out-put. The present studies were designed to test the pulmonary circulatory dynamics under the condition of acute induced hypercapnia in human subjects with pulmonary disease. On the other hand in animal experiment, the animals were examined under two times con-trolled hyperventilation than resting ventilation using a body respirator where their pulmonary circulatory dynamics were not influenced by the change of respiratory pattern. Method s 1) In human subjects Twenty patients with chronic obstructive pulmonary disease were examined for the pulmonary circulatory dynamics at 20 to 40 minutes after inhalation of 4.5 per cent of carbon dioxide. 2) In experimental animal Five healthy dogs were tested under two times controlled hyperventilation with air (hypocapnia), breathing 4 per cent of carbon dioxide (isocapnia), and 10 per cent of carbon dioxide (hypercapnia) in a body respirator of our design. Results A) In human subjects 1) There were no marked change in the wedge pressure of pulmonary artery by breath-ing 4.5 per cent of carbon dioxide with the exception of 3 cases. The mean pressure of pulmonary artery slightly increased from 17.1 to 19.2 mmHg, however, no cases rose as high as above threshold value of 40 mmHg. The pressure of the right ventricle increased in 18 patients, and inthe remaining 2 cases the pressure was unchanged. The mean value of end-diastolic pressure was increased by 2.8mmHg. 2) Before inhalation, the mean cardiac index of these patients was slightly higher than that of normal subjects, the average value being 4.05 l/min/m². After inhalation, 12 of 19 patients showed decreased values. Almost all decreased cases already had hypercapnia before inhalation, otherwise showed hypercapnia after inhalation and a rise in end-diastolic pressure of the right ventricle was observed.

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While the effects of reserpine on hypertension in systemic circulation is well known, there have been a few papers on pulmonary circulation. In this paper pulmonary artery pressure response and changes in respiratory functions caused by the administration of reserpine in patients with pulmonic and cardiac disease were studied. Materials and Methods Twenty-seven male and 8 female patients, from 1 1 to 67 years old, were investigated. They were divided into following groups. Thirteen patients with chronic pulmonary disease (3 patients with bronchial asthma, S with chronic pulmonary emphysema, 2 with bronchiectasis, 2 with pulmonary fibrosis, and one with chronic bronchitis). Ten patients with acquired heart disease (4 patients with mitral stenosis, 3 with mitral steno-insufficiency, one with aortic stenosis, and one with aortic insufficiency). Ten patients with congenital heart disease (3 patients with VSD, 3 with ASD, and 4 with pulmonic stenosis), and 2 patients with essenti-al hypertension. Right heart catheterization was performed in the usual manner, then 1 to 2 mg reserpine was injected intramuscularly. Pulmonary circulatory and respiratory functions were observed before and 90 minutes after reserpine injection. In particular, pulmonary artery mean pressure, wedge pressure, and brachial artery pressure were measured at 30, 60, and 90 minutes after reserpine administration. Results I. Respiratory Function. 1) Heart rate (HR) and minute ventilation (VE/M²) After reserpine injection, there were no significant changes in HR and VE/M² in most of the patients. 2) Arterial oxygen saturation (SaO₂) After reserpine injection, SaO₂ decreased on an average of 6 per cent in patients with chronic pulmonary disease, 3 per cent in patients with acquired heart disease, 1 per cent in patients with congenital heart disease and 5 per cent in patients with essential hypertension.

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Recently the Frank lead system has been chosen in our country as a common method for recording spatial vectorcardiograms among a number of lead systems. Several studies on normal Frank vectorcardiograms have been reported. They were, however, focused on analysis of QRS S_E loops, and few detailed studies were found in the literature. In the present study an attempt was made to establish normal ranges for various parameters of TSE loops. The material consisted of 1 16 normal male adults with the ages ranging from 20 to 35 years (the average age of 2 7.5 years). A11 vectorcardiograms were recorded with the Frank lead system and the chest electrodes were arranged at the 5th intercostal space at the sternum. The frontal, horizontal and left sagittal planar loops were simultaneously photographed on 35-mm films. Enlarged prints were used for exact and easy measurements. The following quantitative and qualitative parameters were analysed. I Analysis of three planar projection T and QRS loops. i) Directions and magnitudes of maximum T and QRS vectors. (Fig. 1) ii) T-QRS angles-maximum T vector angle minus maximum QRS vector angle in each plane. iii) T/QRS ratios-magnitude ratios of the maximum T vector to the maximum QRS vector in each plane. iv) Width of T loops-it was considered positive when the T loop was inscribed counter-clockwisely and negative when this rotated clockwisely. v) W/L ratios of T loop-ratios of width to magnitude of the maximum vector for the T loop. vi) Configuration of T Ioops. II Analysis of spatial T and QRS vectors. i) Spatial polar coordinates of spatial maximum T and QRS vectors (Fig. 2). ii) Spatial T-QRS angles-spatial angles between both spatial vectors. iii) Spatial TIQRS ratios-magnitude ratios of spatial maximum T vector to spatial maxi-mum QRS vector.

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From the embryological point of view, the heart and superior venae cavae of mammalian species originate from the same kind of "anlage. " And the muscle layer of the superior venae cavae proximal to the heart is composed of the smooth muscle and the striated muscle of the cardiac type which continues from the atrial musculature^l4. However, such a striated muscle is not seen in the inferior vena cava^l4 In 1963 MASHIBA and his coworkers reported that the sinus impulses spread not only to the atrium, but also to the superior venae cavae, transmembrane action potentials could be recorded from these vessels and no transmembrane potential was recorded from the inferior vena cava. It is at an important tissue whether the action potentials of the superior venae cavae reported previously are derived from the smooth muscle or the striated muscle of the cardiac type. The musculature of the superior venae cavae proximal to the heart is considered from its location to show the intermediate properties between the cardiac muscle and the vascular smooth muscle. Moreover, the comparative study of the electrophysiological properties between the cardiac muscle and the vascular muscle is an important subject to make clear the function of the cardiovascular system. From these viewpoints, the studies were performed especially on the configuration and electrophysiological characteristics of the action potential of the superior venae cavae. Method s About fifty rabbits, weighing 1.5 to 2.S kg, were used. After the intraperitoneal injection of pentobarbital sodium, the rabbit was thoracotomized under artificial respiration. Three venae cavae were cut at 2-4 cm distal sites from each cardiac orifice, and the atriocaval preparation was made and fixed in a vessel with thermostat at the in situ length. It was irrigated with oxygenated Tyrode solution at a constant flow and constant temperature (36°C. The preparation was electrically driven at the constant frequency (2c/s). The composition of Tyrode solution is as follows : NaC1 137 mM, KCI 2.68 mM, CaCl₂ 1.82 mM, MgC1₂ 1.05mM, NaHCO₃ 11.9 mM, NaHPOI 0.42 mM and C6H1206 5.56 mM. In all experiments, the transmembrane potentials were recorded from 10-20 mm distal sites of the left superior vena cava and about 5 mm distal sites of the right superior vena cava from each cardiac orifice. The arnplitude, the rate of rise and the duration of the transmembrane potentials were observed and measured. In some experiments, temperature, frequency of electrical stimulation and ionic environment were changed. Moreover, in order to observe effects of epinephrine, atropine and acetylcholine on the transmembrane potential, these drugs were added to the solution.

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